若a是有理数,则|a|一定（ ）

题目

若a是有理数,则|a|一定（ ）
A是正数 B不是正数 C是负数 D不是负数
已知ab互为倒数,cd互为相反数,且|x|=4,求式子2ab-(c+d)+x的值.
将下列含有相同发音的单词归类,单词可重复使用.
it big has very his five bag is bike desk kite sit save kid have
/ai/_______________________
/i/________________________
/s/_______________________
/z/_______________________
/v/_______________________

答案

1 D.2.5或-3
3,1 five bike
2it big his is kite sit kid
3 desk sit save
4 has is
5 very five save have